Abstract
Microencapsulation of flavor is an essential technology of enclosing liquid flavor compounds in a carrier matrix to provide protection against the loss of flavors and degradative reactions during food processings. In this review, two encapsulation techniques were discussed; molecular encapsulation in cyclodextrin and microencapsulation by spray drying. Cyclodextrins can include various molecules into their hydrophobic structural cavities to form inclusion complexes. The presence of water is essential for the formation of inclusion complexes between cyclodextrins and guest molecules. There exists a minimum number of water molecules required for inclusion to occur. The release of the encapsulated flavors was markedly dependent on the relative humidity, indicating that water is also an essential factor for release. The retention of flavors during spray drying was dependent on the size of emulsion in the feed liquid. The rate of release and the rate of oxidative reaction were markedly influenced by the relative humidity. This implies that the storage stability of the powders has intimate relations with the changes of matrices structure of the particles, and the glass transition temperature of wall matrices. Confocal laser scanning microscopy (CLSM) was proposed for investigating the cross sectional structure and the release behavior of flavor emulsions in spray dried particles.
